Four steps of research are conducted in order to analyze a relationship between robot’s actions and human’s emotions who is taking a look at an acting robot. First, 138 physical properties of robot’s movements are measured by using a simple humanoid robot with upper half of the body with three degrees of freedom (DOF) in each arm and three DOF in head. Second, from the 138 physical properties, ten typical physical properties are selected by use of hierarchical cluster analysis. Third, sensory evaluation is conducted to extract three emotional factors by use of factor analysis. Finally, the relationship between three emotional factors and ten typical physical properties are analyzed by use of multi regression analysis. By conducting those steps, a model is made explaining the relationship between the physical properties of gesture and the human’s emotions. This model is expected to be used to generate gestures that can give rise to desired emotions of humans.